Flail mower PTO RPM - margin of power

   / Flail mower PTO RPM - margin of power #1  

PxP

New member
Joined
Dec 11, 2016
Messages
6
Location
Poland
Tractor
New Holland
Hello.
I want to buy Perfect BKM-150 flail mower and use it mounted frontally with my New Holland T4050N.
That flail mover requires tractor to have 40HP and my NH has more than 2x of it - 97HP
BKM-150 has 3 gearboxes to choose from when buying - 540/750/1000 RPM.
Tractor front PTO has only 1000 RPM mode, but my idea is to select 540 RPM mower gearbox.
With such margin of HP, my tracor with only 540 RPM (actual) on frontal PTO - will still have
more than needed 40HP for BKM-150 (abt. 1300 RPM on engine actual - /2300 RPM is maximum/)
Additionally with 540 RPM gearbox - it will be easy for me to use it with my older,
weaker tractors (40HP-50HP) that have only 540 PTO RPM at back.
Of course that`s theory.What do You think - will it actually work?
 
   / Flail mower PTO RPM - margin of power #2  
No and why would you? What are you trying to save ? The task is a few hours clipping grass not operating 24/7 for months at a time powering an irrigation pump,base load electrical generation or marine propulsion. The 750 would be do able but now the mower is an orphan .
 
   / Flail mower PTO RPM - margin of power
  • Thread Starter
#3  
No and why would you? What are you trying to save ? The task is a few hours clipping grass not operating 24/7 for months at a time powering an irrigation pump,base load electrical generation or marine propulsion. The 750 would be do able but now the mower is an orphan .

Actually clipping not grass only, but branches from orchard winter/summer prunning. Not few hours, but quite opposite - about 60 hectares of orchards - so more than 200km of driving and mowing branches at least 2 times per year + grass mowing 3-4 times(more than 1000km a year).
So then - will 540 RPM gearbox be OK or not?

Regards.
 
   / Flail mower PTO RPM - margin of power #4  
Not. Tractor will be lugging with boggy throttle response. We regularly have people here who want to operate a 540 rpm pto generator on a throttled back 1000rpm tractor. Unless the tractor is more than 3X over size and better 4+ times over size . The tractor boggs and can't maintain rpm when starting motors etc.
 
   / Flail mower PTO RPM - margin of power #5  
If I understand what you propose correctly, the flail rotor speed would only be slightly more than half the designed rpm. Very likely much too slow to get a satisfactory cut when mowing. Vic
 
   / Flail mower PTO RPM - margin of power #6  
If I understand what you propose correctly, the flail rotor speed would only be slightly more than half the designed rpm. Very likely much too slow to get a satisfactory cut when mowing. Vic

Flail speed will be rated rpm. Depending on the gear Box the tractor engine rpm will be at rated, 2/3 or 1/2 of rated engine rpms.
 
   / Flail mower PTO RPM - margin of power #7  
No clue, but am interested in why you want to use a flail on the front instead of the rear which is more of the standard and more flexible with other tractor usage? I seldom run a flail at full PTO 540 RPM anyway. Mine runs fine a few hundred RPM less at the tractor unless I need to mow very dense, wet and heavy stuff and uses the heavier hammer blades.
 
   / Flail mower PTO RPM - margin of power #8  
Does it rotate the right way? Can't tell you how many people have run into that snag.

I wouldn't do it. I run a little 917 Ford with a 70 HP JD. A little overkill but who cares?

I also might be worried about the potential to overspeed the mower. Maybe not you but someone else.

I never even noticed that it is a perfect mower. I have such a ditch bank mower. Maybe ten pound hammers. Terrible for stones as you can't repair the hammers, but it's good quality equipment.
 
   / Flail mower PTO RPM - margin of power #9  
Picture of my "PERFECT" Baby, just after I got it, before sandblasting, repairing and paint.

View attachment 491404
 
   / Flail mower PTO RPM - margin of power #10  
It might work if your tractor had a hydrostatic transmission.

I have no experience with the Power Shuttle:



nh.JPG
 
 
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